Pleural effects of tremolite in north-west Greece

Our plain-English summary of Pleural effects of tremolite in north-west Greece, by T. Bazas (Lancet, 1987).

The study

• Author: T. Bazas
• Journal: Lancet
• Published: 1987;1(8548):1490-1
• Type of article: Letter
• Read it: PubMed · Publisher
• In J-M's library: Johns-Manville's company medical library held a copy (J-M no. 002548).

In plain English

This is a letter to the editor, not a new study. The author responded to a report by Langer and colleagues on pleural calcification in north-west Greece, saying their account of the author's group's earlier work was inaccurate and incomplete. The author then described that earlier work. A 1980 epidemiological study of a 15% random sample (408 people) from the villages of Metsovo, Anilio and Milea found 28% had pleural calcification. Scanning electron microscopy of a surgical specimen from one man with pleural calcification, born and living in Milea, found small proportions of tremolite fibres. The group proposed tremolite as a cause and noted that geological maps showed serpentine-bearing rock in the area. A review of death registrations for 1969-1978 in these villages found no cases of mesothelioma. The group also found that forced vital capacity (FVC), a lung-function measure, did not differ significantly between people with and without calcification. The author suggested that Langer and colleagues' higher figure of 46% among 268 people X-rayed at a local hospital might reflect selection bias. The author also suggested that the lung-function decrements they reported could come from using non-Greek reference values.

We wrote this plain-English summary from the full article with the help of AI, and a second AI model checked each sentence against the article. It is not the authors' wording; the abstract and the article are their own account.

What the study did and found

• Design: Letter to the editor (correspondence) responding to Langer et al. It summarizes the author's group's earlier epidemiological study and is not a new study.
• Who was studied: In the author's group's earlier study, a 15% random sample (408 subjects) of the population of the villages of Metsovo, Anilio and Milea, north-west Greece, studied in 1980.
• Exposure: Tremolite fibres, proposed as the cause of pleural calcification. Geological maps showed serpentinite (spelled 'serpentenite' in the letter) in the ground of the area.
• Main results:
  • Pleural calcification was found in 28% of the 408-person random sample in 1980.
  • Small proportions of tremolite fibres were found by scanning electron microscopy in a surgical specimen from one man with pleural calcification who was born and still resident in Milea.
  • Death registration statistics for the affected villages for 1969-1978 did not reveal any cases of mesothelioma.
  • FVC values did not differ significantly between subjects with and without calcifications, by analysis of covariance.
• The authors' conclusion: The author argued that the higher 46% prevalence among 268 people X-rayed at the local general hospital, reported in later work, could reflect selection bias. The author also argued that the abnormal FVC values reported by Langer et al could be due to reference equations based on 'foreign' populations, noting that Greek vital capacity values are lower than European values.

Topics

The National Library of Medicine indexes this study under subjects our site covers: Pleural plaques and thickening, Tremolite.

Medical terms in this study, explained in our Lexicon: Tremolite.

Related studies

• Tremolite whitewashing and pleural calcifications — S.H. Constantopoulos, N.A. Saratzis, et al. (1987)
• Association of Metsovo lung and pleural mesothelioma with exposure to tremolite-containing whitewash — A.M. Langer, R.P. Nolan, et al. (1987)
• Metsovo lung outside Metsovo. Endemic pleural calcifications in the ophiolite belts of Greece — S.H. Constantopoulos, P. Theodoracopoulos, et al. (1991)
• An epidemiological study in an Anatolian village environmentally exposed to tremolite asbestos — Y.I. Baris, N. Bilir, et al. (1988)
• Radiological survey of past and present vermiculite miners exposed to tremolite — J.C. McDonald, P. Sebastien, et al. (1986)
• Malignant pleural mesothelioma from nonoccupational asbestos exposure in Metsovo (north-west Greece): slow end of an epidemic? — K. Sakellariou, V. Malamou-Mitsi, et al. (1996)

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